Redirecting to /bin/systemctl start vsftp.service Failed to start vsftp.service: Unit not found.
应该是和centos的版本原因有关系，命令有一些改变
将 service start vsftp 改为 systemctl start vsftpd.service 即可
其他命令：systemctl stop vsftpd.service 停止
systemctl restart vsftpd.service 重启
